Inclusion Criteria:

- Must have had a histological verification of solid tumor at the original diagnosis.
For patients with brain stem gliomas and optic pathway tumors, the requirement for
histological evaluation may be waived. The patient's disease must be considered
refractory to conventional/standard therapy, or a disease for which no conventional
therapy exists and is progressive. Patients must have measurable disease for this
study.

- Agree to having a central venous access placed

- Be between 2 and 18, inclusive, years of age

- Aspartate aminotransferase and alanine aminotransferase less than 2.5 x ULN-

- Total bilirubin less than 2.0 x ULN

- Serum creatinine less than 2.0 mg/dL or a creatinine clearance or glomerular
filtration rate less than 2 times normal for age

- Absolute neutrophil count greater than or equal to 1,000/mm3

- Platelets greater than or equal to 100,000/mm3 (transfusion independent)

- Hemoglobin greater than 8.0 g/dL

- Have an estimated life expectancy of at least 3 months

- Have a Karnofsky performance status greater than 50 for patients aged 10 years or
older and a Lansky performance status greater than 50 for patients aged 2 to less
than 10 years

- Patients are required to have had an EKG, echocardiogram, and pulse oximetry within
age-appropriate levels prior to starting therapy.

- If a woman or man of child producing potential, agree to use effective contraceptive
methods (A negative pregnancy test within 72 hours before the administration of
rhEndostatin protein will be required for women of childbearing potential.)

Exclusion Criteria:

- Patients with leukemia

- Be pregnant or nursing

- Have a history of bleeding diathesis, hypercoagulable condition, or an active
bleeding disorder

- Have any condition that is likely to interfere with regular follow-up

- Have participated in any clinical trial involving conventional or investigational
drugs or devices within 4 weeks prior to rhEndostatin protein administration

- Have received radiotherapy or chemotherapy within 4 weeks prior to rhEndostatin
protein administration

- Have received nitrosourea or mitomycin C less than 6 weeks prior to initiation of
therapy

- Be receiving concurrent treatment with therapeutic doses of heparin or enoxaparin
sodium (Lovenox®) (rhEndostatin protein has a heparin binding domain.)

- Have had major surgery within 2 weeks of starting rhEndostatin protein administration
This does not include placement of a vascular access device.

- Have a history of bone marrow transplantation or extensive radiotherapy
(craniospinal, total body, or radiotherapy to more than half of the pelvis) within
the previous 4 months

- Have ionized calcium levels below the lower limits of normal

- Have a history of myocardial infarction within the last 6 months, angina
pectoris/angina equivalent in the last 6 months (the patient may be on antianginal
medications if the symptoms can be entirely controlled), or have uncontrolled
congestive heart failure

- Have an active infection

- Have additional uncontrolled serious medical or psychiatric illness